UT090 Room temperature and CO2 sensor

Room temperature and CO2 sensor

The room temperature and CO2 sensor contains a temperature measuring element and a NDIR CO2 sensor for measuring of carbon dioxide concentration in  rooms with variable load. The output signals are analogue signals of 2× 0..10 V DC.

Datasheet

The room temperature and CO2 sensor contains a temperature measuring element and a NDIR CO2 sensor for measuring of carbon dioxide concentration in  rooms with variable load. The output signals are analogue signals of 2× 0..10 V DC.

  • Air handling units in rooms with variable load: schools, theatres, auditing halls etc..
  • Monitoring and record of temperature and CO2 concentration in interiors

The temperature is measured by an internal sensor, signal of which is processed in a microprocessor, and converted to normalized analogue output signal. The CO2 value is measured by a communicative NDIR module, and its digital signal is converted to analogue output as well.

The measuring range of the temperature sensor is fixed: 0 to +50 °C. The value is proportional to the signal of 0..10 V at the AO1 terminal. The CO2 measuring range is 0...2000 or 0...5000 ppm, selectable by SW1, the measured value is a 0..10 V signal at AO2. 

Transportation and ageing may cause sensor drift. The sensor records the lowest reading  and expects that at least once per 8 days the CO2 concentration reaches the outside air level (400 ppm). The lowest measured value is then assigned the 400 ppm level. Autocalibration does not work if the room is occupied 24 hours a day, or there are no periods when the gas level drops to background (e.g. greenhouses). Then, the autocalibration function can be disabled by SW2. The autocalibration is set to ON by default.

During the first days of operation, until the first autocalibration, the sensor may read values which differ from the real values by several hundreds ppm, e.g. 200 ppm at night etc. This error is automatically corrected with the first autocalibration.